Ib Physics Chapter 3 Notes

I did non understand how to let off why temperature does not change during a phase change and am not entirely sure if I have accurately or thoroughly described 3. 2. 3 and 3. 2. 4. This is also the case for 3. 2. 12 thermic Physics Thermal Concepts Temperature (T) is a measure of how hot or shivery an object is, and it is the temperature that determines the determines the direction of thermal might transfer between both objects. It is a scalar quantity and is measure in degrees celcius (C ) or kelvin (K). 0 C is equal to -273K.Kelvin is based on the properties of a gas. Thermal energy is the receiving of energy from a hot automobile trunk by a cold body when placed next to from each one other. native energy of a substance is the total potential energy and hit-or-miss kinetic energy of the subatomic particles of the substance. It is where whits in a body gain energy intern eachy and argon able to be course faster ( make up KE) and move apart (increased PE) from work being guessed upon it. Moles A mole of whatever worldly contains 6. 022? 1023 atoms or molecules. This is also known as Avogadros constant. However, all moles dont have the same mass due to the contrary types of particles which have different mass Thermal Properties of Matter precise Heat Capacity (C) of a literal is the tot of catch fire needful to raise the temperature of 1kg of the material by 1C. It is metric in J ? C / kg. It is expressed by the equation c = Q/ m? T where m is mass, Q is the quantity of take fire and ? T is the change in temperature. Thermal Capacity (c) of a material is the join of heating dodge needed to raise the temperature by 1C.It is measured in J / C . It is expressed by the equation C = Q/ ? T where Q is the quantity of heat added and ? T is the amount of increase in temperature of a body. The physical difference between liquids, solids and gaseous phases in scathe of molecular structure and particle motion involve atoms having KE and having strong attracter to each other when solid and having both KE and PE with less attraction and more means to move around when liquid with even more PE and increased potential to move around when gaseous.Evaporation is the change of state of matter from a gas to liquid, whereas boiling is the change of state from liquid to a gas. Specific Latent Heat (L) of a material is the amount of heat required to change the state of 1kg of the material with forth change in temperature. It is measured in J / kg. It is expressed by the equation L = Q/m where Q is the amount of energy and m is the mass. Kinetic Model of an Ideal Gas force per unit ara = force/area The assumptions of the kinetic model of an ideal gas are The Molecules are perfectly elastic The Molecules are spheres The Molecules are identical in that respect is no force between the molecules (excepting collision) with constant velocity between collisions. The molecules are very small Temperature is hence a measure of the ave rage random kinetic energy of the molecules of an ideal gas as the speed of particles increase as the temperature rises. Thermodynamics Thermodynamics relates to a thermodynamic system this is a collection of bodies that canful do work on and exchange heat between each other. These laws apply to all systems. K is absolute zero temperature, where molecules do not move The equation of state for an ideal gas PV = nRT where n is the issuance of moles and R is the molar gas constant. A actually gas molecule has a shape and a finite size, whereas an ideal gas molecule (imaginary) is a point with no shape and it occupies no space. A real gas molecule interacts with others. An ideal gas molecule reacts totally self-reliant of all others. There are no ideal gas molecules, solitary(prenominal) real gas molecules. However, as pressure decreases and the temperature increases, real gas molecules act more like ideal gas molecules.Thermodynamic Processes The expression for the work touch on in a garishness change of a gas at constant pressure P? V where P is pressure and V is volume According to the law of conservation of energy, energy cannot be created or destroyed. Hence, the first law of thermodynamics basically states that as a gas expands and gets hot, heat must have been added Q = ? U + W where ? U is the increase in internal energy, W is the work done by the gas and Q is the amount of heat added to a gas. Examples of changes of state of an ideal gas Isobaric (Constant pressure contraction) Isochoric/Isovolumetric (Constant volume increase in temperature) Isothermal expansion Adiabatic contraction The insurgent Law of Thermodynamics The second law states that it is not possible to convert heat completely into work, implying that thermal energy cannot spontaneously transfer from a component part of low temperature to a region of high temperature. Hence, it is about the spreading out of energy. Entropy Entropy is used to quantify this second law. Entropy is expressed by the equation ?S = Q/T where ? S is change in entropy and Q/T is the quantity of heat flow into a body at a certain temperature. It is measured in J/ K The second law in terms of entropy changes states that in any thermodynamic process the total entropy always increases Even though locally entropy whitethorn decrease, the total entropy of a system will always increase. i. e. the stock in a fridge may get colder and the molecules become more ordered, with entropy in the fridge fall however the total entropy of the room will increase and the room will gain heat.